74676-8

LOINC 2.82

Carbapenemase [Type] in Isolate by Carba NP

Carbapenemase Islt

Definition

  • The Carba NP (Carbapenemase Nordmann-Poirel) test rapidly (<2 hrs) detects carbapenemase production in isolates of Enterobacteriaceae and Pseudomonas aeruginosa. Carbapenemases are detected and can be differentiated by the CarbaNP test when the test isolate produces the enzyme (in the absence of a chemical inhibitor) that hydrolyzes imipenem (a carbapenem antibiotic) into the carboxylic form of the antibiotic, thereby lowering the pH of the reaction solution which contains phenol red indicator. The acidification changes the red color of the reaction solution to orange-yellow color (positive result) that can be visualized easily with the naked eye. Carba NP testing can detect the following carbapenemase types: Klebsiella pneumoniae carbapenemase (KPC; Ambler class A); Verona integron-encoded metallo-β-lactamase (VIM), imipenemase (IMP), New Delhi metallo-β-lactamase (NDM) (all Ambler class B); and oxacillinase-48 (OXA-48; Ambler class D). For this test, each test isolate is inoculated into 4 reaction wells or tubes: one without any antibiotic or chemical inhibitor against carbapenemases, one containing imipenem without any chemical inhibitor, one containing impenem and tazobactam (which inhibits KPC carbapenemases), one containing imipenem and EDTA (which inhibits VIM, IMP, and NDM carbapenemases). Based on the presence and absence of color change among the 4 reaction wells or tubes, one can differentiate among the 3 classes of carbapenemases. However, differentiation is not possible with this test in isolates that produce more than one class of carbapenemases simultaneously.

Component

  • Carbapenemase

Specimen / system

  • Isolate

Class

  • MICRO

Property

  • Type

Scale

  • Nom

Method

  • Carbapenemase Nordmann-Poirel

Related names

  • carbapenem-resistant Klebsiella pneumoniae; CRE; CRKP; Hodge test; ID; Infectious Disease; InfectiousDisease; Islt; Isol; Microbiology; Nominal; Point in time; Random; Typ

Index terms

  • carbapenem-resistant Klebsiella pneumoniae
  • CRE
  • CRKP
  • Hodge test
  • ID
  • Infectious Disease
  • InfectiousDisease
  • Islt
  • Isol
  • Microbiology
  • Nominal
  • Point in time
  • Random
  • Typ